Field
Exemplary embodiments relate to a thin film transistor array panel, and in detail, relates to a thin film transistor array panel including a metal pattern under a semiconductor layer.
Discussion of the Background
A thin film transistor (TFT) is used in various electronic devices such as a display device and the like. For example, the thin film transistor is used as a switching element or a driving element in the display device such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display.
The thin film transistor includes a gate electrode, a source electrode, a drain electrode facing the source electrode, and a semiconductor electrically connected to the source electrode and the drain electrode, and the semiconductor is an important factor for determining a characteristic of the thin film transistor.
Silicon (Si) is a widely used material for a semiconductor. Silicon is classified into amorphous silicon and polysilicon according to its crystal form. Amorphous silicon has a simple manufacturing process, but provides low charge mobility, so it has limitations in manufacturing high-performance thin film transistors. Polysilicon has high charge mobility, but requires a manufacturing stage for crystallizing the silicon, so its manufacturing costs are higher and the process is more complicated.
In a crystallization process of polysilicon, a hillock is formed in a polysilicon layer surface. The hillock is non-uniformly arranged such that a large deviation in the hillock distribution on the thin film transistor may be caused.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.